The present invention relates generally to cooling systems. More particularly, the present invention relates to cooling systems for regulating the temperature of electronic components of electronic devices. The present invention is particularly, but not exclusively, useful for a cooling system for regulating the temperature of electronic components of blade servers.
The regulation of the temperature of electronic components like processors due to heat generated inside the housing of an electronic device like a blade server is an important consideration during the design of an electronic device. Cooling is important because if left unchecked, heat can cause electronic devices to malfunction during use or lead to premature device failure. As improvements in processor size and speed occur, the amount of heat generated by the larger and faster processors also increases. Additionally, improved processors require larger power supplies and auxiliary components that generate increased amounts of heat require improved systems for heat removal.
Another factor that aggravates the need for improved heat removal cooling systems is the trend towards making computing devices such as blade server smaller and especially thinner. The trend toward smaller and thinner electronic devices having larger, faster processors renders the traditional heat removal cooling systems inadequate for several reasons. First, smaller devices having faster processors result in an increased density of heat producing electronic components leading to higher localized concentrations of heat. Also, a decreased amount of space is available for localized temperature regulating devices such as traditional heatsinks. Lastly, a decreased amount of space is available to create ventilation paths that pass by heat sources. Thus, traditional blower assemblies having an inlet from above the blower that ventilate the entire housing of the device are less effective or inapplicable in removing heat when used in smaller, thinner devices.
There are numerous design of cooling systems for electronic device that include a blower assisted heatsink located directly at the electronic component. These conventional coolers had been using axial or radial blower mostly. But, in spite of relative high blower efficiency at regular size of axial and radial blowers, the blower efficiency drop down dramatically when these blowers have been used for relative small size cooling systems.
To overcome such problem there are some conventional coolers that had been using a crossflow blower assisted heatsink. The crossflow blowers have one special feature—blower efficiency is not depend on blower size, therefore the crossflow blower efficiency is significant larger than axial or radial blower ones when using at cooler design. Therefore, the crossflow blower cooler could deliver more air at other equal conditions and has larger thermal efficiency in comparison with conventional axial or radial blower coolers.
It is known cooler for electronic devices that uses crossflow fan (see U.S. Pat. No. 6,227,286 FIGS. 15A-15C and 40A-40C). At this design a crossflow fan axis located perpendicularly to cooler surface that connected to an electronic component. Using this type fan gives the possibility to suck and discharge air at the sides of the fan; therefore the thickness of the apparatus can be reduced. But, the design described in this invention doesn't have high fan efficiency because there is a hub inside a fan impeller where a fan motor is located.
The closest analogue to the invention being claimed is crossflow cooling device for semiconductor components that uses crossflow fan with an axis located parallel to cooling device surface that contacted to a semiconductor component (see U.S. Pat. No. 6,047,765). This device needs an electric drive mounted at a shaft outside of an impeller, therefore increasing dimensions of the cooling device.
Thus, the main problem arise when using the crossflow blower assisted heatsink—on the one hand the placing of the electric drive inside of the blower impeller leads to sufficient decreasing of the blower and thermal efficiency, and on other hand the placing of the electric drive outside of the blower impeller leads to sufficient increasing in size.
Thus, it would be generally desirable to provide an apparatus that overcomes this problem associated with crossflow blower assisted heatsink devices, and has a relatively high blower and thermal efficiency without the need of increasing the volume.